This invention relates generally to the area of plant molecular biology and more specifically to plant viral expression vectors.
Plant virus-based vectors for expressing heterologous proteins in plants present promising biotechnological tools to supplement conventional breeding and transgenic technology. Considering the speed with which a virus infection becomes established throughout the plant and the high yield of viral-encoded proteins that accumulate in plants, the use of viral vectors provides an attractive and cost effective means for the overproduction of valuable proteins in plants and for rapid evaluation of new traits.
Several different types of positive sense RNA plant viruses have been developed as vectors for production of recombinant proteins and peptides (Pogue et al., Annu. Rev. Phytopathol. 40:45-74 (2002); Scholthof et al., Annu. Rev. Phytopathol. 34:299-323 (1996)). Depending on the structure of the viruses involved and their genome replication and expression strategies, a number of approaches including gene replacement, gene insertion, epitope presentation, and complementation have been utilized. Plant viral vectors are presently available for recombinant protein expression in a wide range of host plants including Nicotiana benthamiana, tobacco, squash, cucumber, wheat, barley, cowpea, Nicotiana clevelandii, Chenopodium quinoa, and Arabidopsis (Allison et al., J. Virol. 62:3581-3588 (1998); Brisson et al., Nature 310:511-514 (1984); Choi et al., Plant J. 23:547-555 (2000); Constantin et al., Plant J. 40:622-631 (2004); Dolja et al., Proc. Natl. Acad. Sci. U.S.A. 89:10208-10212 (1992); Fernandez-Fernandez et al., Virology 280:283-291 (2001); French et al., Science 231:1294-1297 (1986); Gopinath et al., Virology 267:159-173 (2000); Hagiwara et al., J. Virol. 73:7988-7993 (1999); Haupt et al., Plant Physiol. 125:209-218 (2001); Lacomme et al., Plant J. 34:543-553 (2003); Turnage et al., Plant J. 30:107-117 (2002)). Even with these advances, there are only a limited number of plant viral vectors that are suitable for systemic expression of foreign proteins in major crops like soybean. Soybean is a main source of oil and high-quality protein worldwide, and there is critical need for tools that allow for rapid evaluation of new traits involving expression of valuable proteins that confer disease/pest resistance and/or those that enhance the commercial value of soybean.
Thus, there exists a need for reagents useful for expressing heterologous proteins in plants such as soybean and determining the function of plant genes. The present invention satisfies these needs and provide related advantages as well.